Clinical associations of 11-hydroxycorticosteroid suppression and non-suppression in severe depressive illnesses

Glucocorticoids. Mood, memory, and mechanisms

Elevated circulating levels of glucocorticoids are associated with psychiatric symptoms across several different conditions. It remains unknown if this hormonal abnormality is a cause or an effect of the psychiatric conditions. For example, the hypercortisolemia observed in a subset of patients with depression may have a direct impact on the symptoms of depression, but it is also possible that the hypercortisolemia merely reflects the stress associated with depression. Further, rather than causing depression, hypercortisolemia could represent a homeostatic attempt to overcome glucocorticoid resistance. Each of these possibilities will be considered, and correlational and causal evidence will be reviewed. This article will focus on the relationships between glucocorticoids and psychiatric symptoms in Cushing's syndrome, major depression, and steroid psychosis/steroid dementia, as well as the effects of exogenously administered glucocorticoids in normal volunteers. Similarities and differences in the relationship of glucocorticoid hormones to psychiatric symptoms in these conditions will be reviewed. Possible mediators of glucocorticoid effects on the brain and behavior, as well as possible "pro-aging" effects of glucocorticoids in certain cells of the body, will be reviewed. The article concludes with a conceptual model of glucocorticoid actions in the brain that may lead to novel therapeutic opportunities.

Age and the dexamethasone suppression test: results from a broad unselected patient population

We examined the relationship between age and postdexamethasone serum cortisol concentration in 676 psychiatric inpatients with a variety of DSM-III diagnoses. Regardless of diagnosis, patients 65 years and older had significantly higher nonsuppression rates than those below age 65 (64% vs. 34%). The correlation between age and cortisol level was moderate, but significant. Aging is associated with increasing nonsuppression rates to dexamethasone, and this change is augmented by an affective disorder diagnosis. Levels of nonsuppression and age-cortisol correlations vary depending on dose of dexamethasone, diagnosis, and gender.

The dexamethasone suppression test and negative symptoms of schizophrenia

The dexamethasone suppression test (DST) was administered to 28 subjects who met DSM-III criteria for chronic schizophrenia and shared similar environments. Samples were assayed for both plasma cortisol and dexamethasone levels. After controlling for other factors, the mean postdexamethasone cortisol level (MPDC) was correlated with the patients' score on the Scale for the Assessment of Negative Symptoms (SANS). A significant relationship emerged between these 2 parameters, suggesting that the social deterioration seen in chronic schizophrenia is at least partly related to a biological disease process as reflected by the DST. The importance of quantifying the level of dexamethasone in the DST is discussed.

Adrenocortical hyperactivity in depression: effects of agitation, delusions, melancholia, and other illness variables

In an attempt to determine the relative contributions to adrenocortical hyperactivity in depression of agitation, delusions, and melancholic subtype, we measured cortisol levels before and after dexamethasone in 93 unipolar major depressed inpatients. Stepwise multiple regression showed that agitation predicted 22% of the variance in a.m. cortisol level after dexamethasone. Addition of the variables melancholia and delusionality to the regression model accounted for 27% and 34%, respectively, of the variance in the same cortisol variable. Age, illness severity, and weight loss added no further significant predictive value. Age, weight loss, and illness severity did affect cortisol levels when examined separately from the other variables. Rate of nonsuppression on the dexamethasone suppression test (DST) differed between the nonmelancholic major depressive group and any other group with melancholia. These results suggest why some discrepancies may exist between studies of the DST in delusional depression and indicate that agitation merits careful assessment in future studies of DST response.

Prediction of outcome in depressed patients by weekly monitoring with the dexamethasone suppression test

Forty-three depressed patients in hospital were studied with weekly dexamethasone suppression tests (DSTs) and were followed as out-patients for at least three months after discharge. The detection rate of patients with LHPA axis dysfunction increased from 41% with a single DST to 59% with serial DSTs. There was a poor correlation between weekly post-dexamethasone cortisol levels and Hamilton depression rating scores. In patients with evidence of LHPA axis dysfunction, a DST at discharge discriminated effectively between a good and a poor outcome group; persistent non-suppression was strongly linked with a relapse of depression in the first three months after discharge. In general, our results support previous claims that the DST is a state marker for depressive illness.

The relationship between age and post-dexamethasone cortisol: a test of three hypotheses

Previous studies report that DST nonsuppressors are older than normal suppressors. Data are presented on 188 primary unipolar major depressive inpatients and 35 healthy controls. In males, age appeared to correlate positively with post-dexamethasone cortisols in depressed patients and normal controls, although mean levels were higher in depressives. Female controls showed no consistent relationship between age and post-dexamethasone cortisol. A positive relationship did exist for depressed women. However, the association disappeared when age-of-onset was entered into the model, suggesting that in females early onset may identify a subtype of depression with normal DST suppression.

Body weight and reported versus measured weight loss as confounders of the dexamethasone suppression test

We examined the association between post-dexamethasone suppression test (DST) serum cortisol and body weight, self-report of weight loss during the episode, and measured weight loss during the first week of admission in a series of 245 depressed inpatients. Data on measured weight loss between two successive admissions was available in a group of 57 depressed inpatients. Reported weight loss during the episode and measured weight loss during the first week of admission were not related to DST nonsuppression. In contrast, DST nonsuppression was significantly more frequent in patients with measured weight loss between two successive admissions. This association was particularly strong in patients with below-average body weight and was practically nonexistent in patients with above-average body weight. Multivariate analysis indicates that a significant association between DST results and weight loss may be missed if self-report is substituted for direct measurement of weight loss and if potential confounders, such as total body weight, age, and sex, are ignored.

Relationships of the dexamethasone suppression test to clinical severity and degree of melancholia

Investigators continue to debate whether the Dexamethasone Suppression Test (DST) reflects clinical severity or degree of melancholia ("endogeneity"). To evaluate this question, we studied 73 drug-free inpatients diagnosed with Schedule for Affective Disorders and Schizophrenia/Research Diagnostic Criteria (SADS/RDC) as having major depressive disorder (MDD). We compared absolute and dichotomous DST values (DST suppression versus nonsuppression) with absolute and dichotomous measures of endogeneity (as measured by operationally defined RDC items) and with Hamilton Rating Scale for Depression (HRSD) scores that were collected immediately prior to treatment. We found that degree of endogeneity correlated moderately (r = 0.27) but significantly (p = 0.02) with absolute DST values; DST nonsuppression increased proportionately with changes in categorical endogenous subtype (0% of the nonendogenous patients were nonsuppressives, 52% of probable endogenous, and 61% of subjects definitely endogenous); mean values for maximum DST concentrations increased steadily with categorical endogeneity (nonendogenous, 1.44 microgram/dl; probable endogenous, 7.65 micrograms/dl; definite, 10.93 micrograms/dl; p = 0.01); HRSD scores correlated more strongly (r = 0.45, p = 0.000) with maximum DST levels than did the degree of endogeneity. Age and weight changes did not account for the relationship of endogeneity to DST values. These data suggest that maximum postdexamethasone plasma cortisol levels reflect overall severity of depression and endogeneity and that endogeneity per se is highly confounded with severity.

Plasma cortisol, the dexamethasone suppression test and depression in normal adult males

This study of 33 normal adult males investigated the nature of relationships between plasma cortisol levels and depression. Both plasma cortisol levels and responses to the Dexamethasone Suppression Test (DST) have been shown to be associated with clinical depression. However, relatively few studies have investigated the utility of either plasma cortisol measures or the DST for evaluating emotional distress in subjects without demonstrable psychiatric morbidity. The results of this study suggest that the traditional DST has little discriminatory power when used with psychologically healthy subjects. Conversely, plasma cortisol was shown to be positively correlated with clinical personality characteristics associated with emotional distress, particularly depression. These data suggest the hypothalamo-pituitary-adrenal irregularities are not only associated with clinical psychopathology but may also be related to emotional reactivity in normal, asymptomatic individuals.

Outcomes on lithium treatment as a tool for genetic studies in affective disorders

From a genetic point of view, the application of mathematical models to affective disorders has not yet been useful, since they do not indicate a specific mode of transmission. To use these models correctly, we need to identify homogeneous genetic subgroups among those sharing the common phenotypic feature of affective illness. Our useful criterion for this is outcome on long-term lithium therapy, since experimental data suggest the existence of a close relationship between the genetic mechanisms that underly the affective disorders and those that underly outcome on lithium. We have studied 145 subjects with primary affective disorders, 92 of whom did not relapse during lithium treatment and 53 of whom did, together with 864 of their first-degree relatives. The data for both groups fit both single major locus and multifactorial polygenic models for genetic analysis, including a sex effect and therefore neither mode of transmission can be excluded.

Cortisol secretion and DST in affective disorders--methodological concerns

In the wake of a large number of studies seeking biological markers for a variety of psychiatric disorders including affective disorders, the enthusiasm over Cortisol Secretion and Dexamethasone Suppression test lead the authors to review critically the data collected so far. The research designs involved, the samples studied and the reliability of the data collected along major variables such as diagnostic criteria, sampling characteristics, procedural differences, length of follow-up and the role of environmental stressors were evaluated. A useful exercise was to compare the literature published in the 50's and 60's with the more recent publications. The potential usefulness of DST as a diagnostic and management tool remains open for scrutiny. Whether the abnormalities in cortisol levels and DST responses evidenced by many researchers are an epiphenomenon or have a diagnostic and management value still remains unclear. From their analysis, the authors point out the lack of well controlled sequential studies using standardized procedures, and large age specific samples. Difficulty arising from the use of various terminologies and criteria for diagnosis of depressive disorders is recognized. The limitations of the use of DST in general clinical practice along with directions for future research are outlined.

Pituitary-adrenal regulation over multiple depressive episodes

Pituitary-adrenal activity was evaluated with the dexamethasone suppression test in 11 patients over their multiple hospitalizations for major depression. All six patients who were suppressors during their index admission had one subsequent admission over the period of study during which they were again suppressors. Of five patients who were nonsuppressors during their index admission, three had one subsequent admission and two had three subsequent admissions. Four of these patients were again nonsuppressors during a subsequent admission. For patients who were nonsuppressors during some but not all admissions for depression, pituitary-adrenal activity appeared related to the persistence of the depressive episodes.

Central nervous system and peripheral effects of ACTH, MSH, and related neuropeptides

Adrenocorticotropic Hormone (ACTH), Melanocyte-Stimulating Hormone (MSH), and related peptides have been shown to have several neurogenic effects: alteration of cerebral protein synthesis, RNA synthesis, protein phosphorylation, and neurotransmitter turnover. Furthermore, there appears to be an ACTH containing circuit in the CNS which originates in the arcuate nucleus. Changes in concentration of the peptides in this family have been shown to alter electrophysiology, neuromuscular function, and behavior (e.g., grooming, learning) in infrahuman subjects. These findings suggest that the neuropeptides MSH and ACTH influence the capacity of an organism to efficiently evaluate information and influence the affective functioning of humans.

Pituitary-adrenal disinhibition in depression: marker of a subtype with characteristic clinical features and response to treatment?

The data from a series of studies in different patient samples are consistent in showing that resistance to dexamethasone suppression is selectively associated with primary major depressive disorder. In addition, nonsuppressors appear to have more depressive episodes, show greater improvement during hospitalization, tend to be older than suppressors, and may have a specific disturbance in cognitive function. Preliminary data suggest that nonsuppressors and suppressors respond preferentially to different antidepressants. These data raise the possibility that pituitary-adrenal disinhibition, as assessed by the dexamethasone suppression test, is associated with a depressive subtype having a distinctive pathophysiology, clinical course, and treatment response.

Effect of hypophysectomy and adrenalectomy on 5-hydroxytryptamine uptake by rat hypothalamic synaptosomes and blood platelets

The effect of adrenalectomy and hypophysectomy on 5-HT uptake by rat platelets and hypothalamic synaptosomes taken from the same animal was studies. The experiments were performed 1-2 weeks after the operations of the shamoperations. After adrenalectomy a significant decrease of 25% in 5-HT uptake by platelets was noted. In synaptosomes there was a similar trend, but the decrease was not significant. After hypophysectomy a significant 25% decrease in 5-HT uptake was observed both in platelets and in synaptosomes. These results suggest that corticosteroid hormones might mediate adaptive changes of 5-HT uptake both in synaptosomes and in blood platelets. Blood platelets have been used as a peripheral model of serotoninergic nerve terminal in studies concerning physiology of monoamines systems. But the present results suggest that also in some pathological conditions changes in platelet biochemistry could reflect those in the CNS neurones.

Neuroendocrine dysfunction in genetic subtypes of primary unipolar depression

Disinhibited activity of the hypothalamic-pituitary-adrenocortical (HPA) neuroendocrine system, characterized most specifically by abnormal responses to the dexamethasone suppression test (DST), is observed in 40-50% of patients with endogenous depression. The heterogeneity of endogenous depressives with respect to this neuroendocrine marker is so far unexplained. A recent report from Iowa suggested that genetic factors could account for this heterogeneity, since abnormal DST reponses were found with widely differing frequencies among primary unipolar depressives subtyped by the genetic criteria of Winokur. We studied 14 patients with primary endogenous delusional unipolar depression. Abnormal DST responses were found in 79% of the entire group, and with similar frequencies among each of the Winokur subtypes. In particular, five of six patients (83%) with depression spectrum disease had abnormal DST results. This contrasts with a frequency of 4% reported by the Iowa group. We conclude that disinhibited HPA activity does occur in depression spectrum disease when a delusional endogenous depression is present. Our results and those of the Iowa study could both be consistent with a threshold model of HPA activation. The high frequency of positive DST results in delusional endogenous depressives may be determined by disinhibited central pain mechanisms. Variations in this clinical dimension, combined with variations in threshold for HPA activation by pain mechanisms, could account for the heterogeneity of DST responses among endogenous depressives.

Resistance to inhibiting effect of dexamethasone in patients with endogenous depression

Suppression of 11-hydroxycorticosteroids (11-OHCS) release with dexamethasone (0.5 mg) has been investigated in 52 patients with endogenous depression and also in normals and in patients with other mental diseases. The suppression was considerably less in depressives (-19 +/- 5%) than in control groups (approx. -60%). The dexamethasone test indices were normalized during remission. The elucidate mechanisms of the dexamethasone inhibiting effect, the influence of tryptophan, DOPA and benzodiazepines on the 11-OHCS level and the degree of its suppression with dexamethasone have been studied. The data indicate a dual effect of serotonin on the regulation of the adrenal function: it stimulates CRF secretion and increases the inhibiting effect of corticosteroids on CRF release. It is suggested that during depression the negative feedback is disturbed in the system - brain monoamines-glucocorticoids. The possible role of this impairment in depression pathogenesis is considered.

Genetic subtypes of unipolar primary depressive illness distinguished by hypothalamic-pituitary-adrenal axis activity

Serum-cortisol response to the 1 mg overnight dexamethasone suppression test was investigated in 86 patients with unipolar primary depressive illness and 80 non-depressed controls (45 with mania and 35 with schizophrenia). The depressed patients were assigned to one of three genetic subtypes according to the family psychiatric history. Resistance to suppression of serum-cortisol by dexamethasone was found in 37 of 86 (43%) depressives and none of the 80 controls. Non-suppression distinguished the three genetic subtypes of depression, being found in 23 of 28 (82%) patients with familial pure depressive disease (F.P.D.D.), 13 of 35 (37%) patients with sporadic depressive disease (S.D.D.), and 1 of 23 (4%) patients with depression spectrum disease (D.S.D.). The three genetic subtypes were further distinguished by the age of onset, with S.D.D. the oldest, and by the number of previous depressive episodes, with F.P.D.D. the most. Severity of depression did not separate the three subtypes. This is the first report of a distinct neuroendocrine abnormality which supports an objectively defined classification of unipolar primary depressive illness. It is suggested that unipolar primary depressive illness is three or more separate illnesses, each with a potentially distinctive mode of inheritance, pathophysiology, neurochemistry, clinical course, and treatment response.

Studies of endocrine activity, plasma tryptophan and catecholamine excretion on psychosurgical patients

The Geoffrey Knight Psychosurgical Unit admits patients on a regular basis and thus offers special opportunities for studying severely ill psychiatric cases, all having one particular treatment under relatively controlled conditions. The opportunity has been taken to repeat various metabolic studies previously reported to be abnormal in some psychiatric illnesses. In the present investigation several measures of endocrinological activity were studied, as was plasma tryptophan, both free and bound. None of these data confirmed reports of abnormalities and neither did the values found at operation help to predict clinical outcome 1 year later, which was another possibility. Urinary catecholamines were also measured and 2 weeks after operation. Male patients, regardless of diagnosis, showed a mean increase in adrenaline output after operation compared with the pre-operative value and this was significantly different from the females, who showed a small mean decrease. The depressed patients showed a significant reduction in noradrenaline excretion after operation compared with before operation and this trend was enhanced in those of good outcome at 1 year, the difference from those who responded poorly being significant. It could be that the ventromedial lesion that is produced alters noradrenaline metabolism or autonomic activity in depression and this possibility merits further study.

The classification of depressive disorders. II. A review of historical and physiological classification studies

A review of recent classification studies of depressive disorders based on historical data and physiological indices was made. It was found that historical variables, such as age of onset and family background, are potentially useful to distinguish depressive subgroups, although these groupings did not differentiate consistently unipolar from bipolar depressives. While the physiological indices do not support the present psychiatric nosology, single physical signs were found to differentiate subgroups within the effective disorders. The implications of these findings for a different research model were discussed.